1. Field of the Invention
This invention relates to magnetic surfaces, and more particularly to a flexible sheet having a magnetic surface. The flexible sheet is safe to handle and able to be cut with common hand tools, such as scissors.
2. Description of the Related Art
In many situations, it is desirable to have a magnetic surface: one to which magnets are attracted and may be attached. For example, in a classroom teachers often must display instructive material to students, but also keep their hands free to write. Large magnetic boards are available for such a purpose, but these must attach to a wall, or rest on an easel.
Magnetic products that are packaged for retail display are commonly mounted to a steel sheet to maintain their relative positions in the package. The steel sheet must be inexpensive, because it will be discarded after it is removed from the packaging. Inexpensive steel sheets are presently sold by Magna Visual, Inc. with MAGNA CHART brand magnetic visual aids. The steel sheets are paper-coated and about 3 to 6 mils thick with admittedly sharp, dangerous edges as evidenced by a warning on the label of the retail packages. The steel is apparently paper coated for appearance purposes and some corrosion resistance, which is due mostly to the adhesive used to mount the paper to the steel.
Sheet steel is also conventionally sandwiched into paper board products for game boards and wall boards sold by Kling Magnetic of Hudson, N.Y. The thickness of the steel sheet ranges from about 3 to 6 mils (0.003 to 0.006 inch). These products are also considered unsafe for ordinary handling due to sharp edges.
In U.S. Pat. No. 5,609,788, Deetz describes a paint composition into which ferrous particles are suspended. Surfaces coated with this paint will attract magnets and hold them in place. Thus, a wall or other surface can be painted to look and function in an ordinary manner, but also provide a magnetic surface. However, the amount of ferrous particles mixed in the paint is limited because the paint must remain spreadable. Therefore, the attraction of a magnet to the painted wall or other surface is relatively small, which becomes a problem if somewhat heavier items must be attached to them. Ten mils of this paint is about 50% as effective in attracting magnets as a 2 mil steel substrate.
Therefore, a long felt need exists for a thin magnetic sheet that is inexpensive, safe for normal or typical handling and convenient to use for a variety of educational, entertainment, and packaging applications which has not been satisfactorily solved by prior efforts.